diff --git a/SMPStaticAnalyzer.cpp b/SMPStaticAnalyzer.cpp
index 13313ce869017bd31072030887b115af58076c53..b123c54095d5f6ba02461df9436d1f952c117056 100644
--- a/SMPStaticAnalyzer.cpp
+++ b/SMPStaticAnalyzer.cpp
@@ -968,7 +968,7 @@ bool MDPatchUnconvertedBytes(ea_t CurrDisasmAddr) {
 			return false;
 		}
 		PatchInstr.PrintOperands();
-		op_t CallDest = PatchInstr.GetUse(0);
+		op_t CallDest = PatchInstr.GetUse(0).GetOp();
 		if ((o_near != CallDest.type) || (0 != CallDest.addr)) {
 			msg("Cannot patch call unless it is call near ptr 0 at %x",
 				CurrDisasmAddr);
@@ -993,7 +993,7 @@ bool MDPatchUnconvertedBytes(ea_t CurrDisasmAddr) {
 	return true;
 } // end of MDPatchUnconvertedBytes()
 
-// Create lists of code addresses identified by IDA Pro (in IDAProLocs)
+// Use the lists of code addresses identified by IDA Pro (in IDAProLocs)
 //  and an external disassembler (in DisasmLocs). Compare the lists and
 //  try to convert addresses to code that are found in DisasmLocs but
 //  not in IDAProLocs. Emit warnings when IDAProLocs has a code address
@@ -1080,6 +1080,7 @@ void FixCodeIdentification(void) {
 				FixupRegion CurrRegion(ConvertRegion);
 				CodeReanalyzeList.push_back(CurrRegion);
 				bool AllConverted = true;
+				bool AllNops = true;
 				do {
 					flags_t InstrFlags = getFlags(CurrDisasmAddr);
 					if (!isUnknown(InstrFlags)) {
@@ -1090,6 +1091,8 @@ void FixCodeIdentification(void) {
 						if (InstrLen > 0) { // Successfully converted to code
 							SMPInstr NewInstr(CurrDisasmAddr);
 							NewInstr.Analyze();
+							if (!NewInstr.MDIsNop())
+								AllNops = false;
 #if SMP_DEBUG_FIXUP_IDB
 #if 0
 							msg("FixCodeID success at %x: len: %d %s\n", CurrDisasmAddr,
@@ -1117,6 +1120,21 @@ void FixCodeIdentification(void) {
 						++DisasmIndex; // skip cleanup loop
 					}
 				} while (CurrDisasmAddr < CurrAddr);
+				if (AllConverted && AllNops) {
+					// We want to convert the region back to unexplored bytes
+					//  and take it off the work list. Regions that are all nops
+					//  create data flow analysis problems sometimes. The region
+					//  is often unreachable code and produces a basic block with
+					//  no predecessors within a function. This often happens when
+					//  an optimizing compiler uses nops as padding to align jump
+					//  targets on cache line bounaries. With no fall through into
+					//  the nops, they are unreachable and should be left as unknown.
+					msg("FixCodeID nops region from %x to %x\n", CurrRegion.GetStart(),
+						CurrRegion.GetEnd());
+					do_unknown_range(CurrRegion.GetStart(),
+						CurrRegion.GetEnd() - CurrRegion.GetStart(), DOUNK_SIMPLE);
+					CodeReanalyzeList.pop_back();
+				}
 			} // end if (SkipArea) ... else ...
 		} // end if (addr < CurrDisasmAddr) .. else if ... else ...
 	} // end while (DisasmIndex <= DisasmLocs.size()
@@ -1176,6 +1194,12 @@ int FixupNewCodeChunks(void) {
 	int changes = 0;
 	for (CurrRegion = CodeReanalyzeList.begin(); CurrRegion != CodeReanalyzeList.end(); ++CurrRegion) {
 		bool AllConverted = true;
+		bool AllNops = true;
+		bool NoFixups = (0 == CurrRegion->FixupInstrs.size());
+		if (NoFixups) {
+			CurrRegion->SetStart(BADADDR);  // mark for removal
+			continue;  // skip to next region
+		}
 		list<ea_t>::iterator CurrInstr;
 		for (CurrInstr = CurrRegion->FixupInstrs.begin(); CurrInstr != CurrRegion->FixupInstrs.end(); ++CurrInstr)  {
 			int InstrLen = ua_code(*CurrInstr);
@@ -1185,7 +1209,10 @@ int FixupNewCodeChunks(void) {
 #if SMP_DEBUG_FIXUP_IDB
 				msg("FixupNewCodeChunks success at %x: len: %d\n", *CurrInstr, InstrLen);
 #endif
-				*CurrInstr = BADADDR; // mark for removal
+				if (!NewInstr.MDIsNop()) {
+					AllNops = false;
+					*CurrInstr = BADADDR; // mark for removal
+				}
 			}
 			else {
 				AllConverted = false;
@@ -1194,13 +1221,22 @@ int FixupNewCodeChunks(void) {
 #endif
 			}
 		} // end for all instrs in CurrRegion
-		if (AllConverted) {
+		if (AllConverted && !AllNops) {
 #if SMP_DEBUG_FIXUP_IDB
 			msg("FixupNewCodeChunks success for region from %x to %x\n",
 				CurrRegion->GetStart(), CurrRegion->GetEnd());
 #endif
 			CurrRegion->SetStart(BADADDR); // mark for removal
 		}
+		else if (AllConverted && AllNops) {
+#if SMP_DEBUG_FIXUP_IDB
+			msg("FixupNewCodeChunks re-converting nops region from %x to %x\n",
+				CurrRegion->GetStart(), CurrRegion->GetEnd());
+#endif
+			do_unknown_range(CurrRegion->GetStart(),
+				CurrRegion->GetEnd() - CurrRegion->GetStart(), DOUNK_SIMPLE);
+			CurrRegion->SetStart(BADADDR); // mark for removal
+		}
 		else {
 			// Remove only the instructions that were fixed up.
 			CurrInstr = CurrRegion->FixupInstrs.begin();